The growing popularity of electronic devices has produced an increased demand for electrical power sources to energize these devices. At present, storage or rechargeable batteries are typically used to provide independent electrical power sources for electronic devices. However, the amount of energy that can be stored in storage or rechargeable batteries is insufficient to meet the need of certain applications.
Fuel cells, including hydrogen/air fuel cells (H/AFCs) have enormous potential as a replacement for batteries. Fuel cells can operate on very energy-dense fuels. Some fuel cell-based power supplies offer high energy-to-weight ratios compared with even state-of-the-art batteries.
Functionally, fuel cells generate electricity by reacting hydrogen with oxygen to produce water. For example, in a PEM H/AFC hydrogen atoms pass through a membrane as H+ while the electrons travel around the membrane, the H+s join with oxygen, on the otherside of the membrane to form water. Since oxygen can typically be obtained from the ambient atmosphere, only a source of hydrogen must be provided to operate a fuel cell. Merely providing compressed hydrogen is not always a viable option, because of the substantial volume that even a highly compressed gas occupies. Liquid hydrogen, which occupies less volume, is a cryogenic liquid, and a significant amount of energy is required to maintain the extremely low temperatures required to maintain it as a liquid. Furthermore, there are safety issues involved with the handling and storage of hydrogen in the compressed gas form or in the liquid form.
Among the most desirable alternative hydrogen sources is hydrogen produced by the steam reformation of hydrocarbons, particularly C1-C4 hydrocarbons. For example, C1, methane, as natural gas, and C3, propane, are used for residential, mobile home and recreational services, while propane and C4, butane, are used as fuels for backpack stoves.
Following are the reaction equations for the steam reforming method, where methane is the feedstock:CH4+H2O→CO+3H2  Equation (1)CH4+2H2O→CO2+4H2  Equation (2)
It is a drawback of the reformation of such hydrocarbon fuels, that coke, a solid residue which reduces the activity and lifetime of the steam reformation and catalyst and is undesirable in a fuel cell application, is formed. Consequently, there is a desideratum for an apparatus and method that has the flexibility to effectively and efficiently generate hydrogen from C1-C4 hydrocarbon fuels without necessitating a change in the catalyst, while minimizing the production of coke residue.